I have looked at a number of schools on CollegeResults. It looks like the transfer out data for many is missing. For example, that box is blank for Central Michigan. For Michigan State it is 12.7%.
A better gauge might be Freshman retention rate. 91% for MSU, 81% for Mich Tech, 77% for Central. MSU has the best 4 year grad rates too, though Tech narrows this for 6 year grad rate.
Reason is tech schools like Mich Tech and NC State and Georgia Tech have so many engineers, as noted above. These majors can take longer to complete, hence the 6 year grad rate maybe being more accurate for them than the 4 year. And for schools even more engineering-based, like Mich Tech, as above poster noted, there are fewer majors to switch to. (Maybe all of these engineering majors are why Mich Tech actually has higher SAT and ACTs than Michigan State, though I’d never heard of Mich Tech until I saw it in the Princeton Guide. They don’t have nationally known football and BB teams, I guess.)